If you sell on Ebay do you claim it on your taxes?

I have a three ring binder that I keep track of all my sold items. How do I do it you may ask. Well I print off the eBay invoice then I go on down to the post office and send off the item, then I keep the sale receipt and delivery conformation receipt. When I get home I staple them all together and three hole punch it and in the notebook it goes. Then I just wait until it's about tax season then I add up all the expenses and profits. Then proceed to fill out tax forms like you normally would.

My eBay sales are all done through my limited company. The for-profit ones anyway, Personal sales I do through the same eBay account, to help add value to it, but I use my personal PayPal account rather than my business one.
If you're buying stuff to sell on eBay at a profit you need to keep track of all costs - stock, postage, packaging, eBay fees and PayPal fees and total sales. I find it easier just to record all the expenses and let the accountant do the actual tax calculation.